Sign in with
Sign up | Sign in
Your question

System Spontaneously Shuts Off - PSU OR Motherboard?

Last response: in Systems
Share
October 24, 2011 3:50:48 AM

Hi guys, I built a system about 8 months ago and about a month ago it spontaneously shut off. I tried to turn it back on but the power button would do nothing. I then switched off the power supply and the next morning turned the power supply back on and pressed the power button and it worked.

I then did not have the problem for a little while but it has since appeared again, and now my system will always spontaneously shut off after a few minutes. I can not just turn it back on. I have to turn the power supply off and wait for a bit and then it will turn on later.

There is display and the system posts after I get it back on again. The CMOS is corrupted at this point and the system automatically reloads the settings. Once it is up again it will shut off after 5-10 minutes always.

First thing I did was take the PSU out. I jumped it with a pin and let it run for about 6 hours. It did not shut off.

I then connected the Motherboard ONLY (no drives, no video card) and powered it up and left it all on. It DID shut off after about 5-10 minutes.

I'm not discounting the PSU because perhaps there could be an issue with it when it is under some load, otherwise I'm thinking it is the Motherboard.

Does anyone know these symptoms or know how to determine if it is a PSU issue or a Motherboard issue? Note: I do not have access to another PSU. Thanks.
a b B Homebuilt system
a b ) Power supply
a b V Motherboard
October 24, 2011 4:02:13 AM

I've heard of problems similar to yours but I don't remember exactly what caused it. Perhaps if you posted your complete system specs someone might recognize the issue and will be able to help you solve it.

CPU?
MOBO?
RAM?
CASE?
PSU?
HDD/SSD? (all of them)
Other connected devices both internal and external.

All details are useful even if not actually relevant.
m
0
l
October 24, 2011 4:27:03 AM

The system specs are:
Intel i3 2.93Ghz
Gigabyte H55N-USB3 Mobo
Mushkin 8GB Silverline Ram
Lian-Li PC-Q11 Case
OCZ ModXstream-Pro 500W
Asus 5770 1GB Video Card
DVD-RW, Intel 128gb SSD, Toshiba 1TB 2.5", Seagate 1TB 2.5"

Note: that currently all videocard/drives are disconnected and it is ONLY PSU and Mobo connected to each other and I am still getting the shutoff.
m
0
l
Related resources
October 24, 2011 10:30:52 PM

anyone have any ideas?
m
0
l
October 25, 2011 1:39:22 PM

It sounds very similar to a problem I just posted about except that mine shuts off after a random amount of time. I don't know if that means it's a completely different problem or a similar one. I was suspecting my UPS because I had an issue before with that UPS and my speakers. Basically, my speakers just shut off one day and would no longer turn on. Then, a few months later I plugged it into a different outlet on my UPS and it has been working ever since.

Is your computer on a UPS?
m
0
l
a b B Homebuilt system
a b V Motherboard
October 25, 2011 2:16:37 PM

If you're getting a cmos error you should try 2 things.

First, turn it off and unplug it from the wall. After you unplug it hold the power button, (on/off) down for a few seconds to drain the excess stored power in the resistors/mosfets and the like. Then take the cmos battery out for about 5 or 10 seconds and reinstall. Plug it back up and turn it on. Go into bios and make sure your hdd settings are on ide or ahci, whichever setting you installed your operating system on. [If you can get into bios before you do this write down your settings first because resetting your cmos will return everything to factory defaults. If you never did any of these things, well, nevermind, lol.] save and exit - reboot. See if that solves the problem.

If that doesn't work then you should update your bios. Mainly because it will install an uncorrupted set on the chip and store them in cmos. if you already have the latest set installed then download a fresh set and reinstall those.

You are correct about the test with jumping the psu. That only indicates whether or not the psu comes on. The other possibility is heat. If you have to wait before you turn it back on it might just be because it needs to cool down. Have you tried removing your cpu heatsink, cleaning all the thermal grease from both sides, reapply and reseat and see how that works. Of course you will want to check the heatsink first to make sure it didn't work loose just from general use. You didn't mention an aftermarket cpu cooler so if you're using the stock cooler with the plastic twist tabs it might have worked itself loose. Check that before you do any thing else since all you have to do it look at it closely.
m
0
l
October 26, 2011 6:33:02 PM

suteck said:
If you're getting a cmos error you should try 2 things.

First, turn it off and unplug it from the wall. After you unplug it hold the power button, (on/off) down for a few seconds to drain the excess stored power in the resistors/mosfets and the like. Then take the cmos battery out for about 5 or 10 seconds and reinstall. Plug it back up and turn it on. Go into bios and make sure your hdd settings are on ide or ahci, whichever setting you installed your operating system on. [If you can get into bios before you do this write down your settings first because resetting your cmos will return everything to factory defaults. If you never did any of these things, well, nevermind, lol.] save and exit - reboot. See if that solves the problem.

If that doesn't work then you should update your bios. Mainly because it will install an uncorrupted set on the chip and store them in cmos. if you already have the latest set installed then download a fresh set and reinstall those.

You are correct about the test with jumping the psu. That only indicates whether or not the psu comes on. The other possibility is heat. If you have to wait before you turn it back on it might just be because it needs to cool down. Have you tried removing your cpu heatsink, cleaning all the thermal grease from both sides, reapply and reseat and see how that works. Of course you will want to check the heatsink first to make sure it didn't work loose just from general use. You didn't mention an aftermarket cpu cooler so if you're using the stock cooler with the plastic twist tabs it might have worked itself loose. Check that before you do any thing else since all you have to do it look at it closely.


I did the battery pull and resetting the CMOS before. I tried resetting it to both factory defaults, and my saved settings. It still has the same problem off shutting off after a little bit of time.

I usually only get around 5-10 minutes before the system shuts down so I'm kinda scared to flash a new CMOS cause it probably won't finish and then I might not be able to boot at all.

I do have an aftermarket CPU Cooler, I've got the SilenX Effizio Cooler and it's not the push pins it's the screw downs and it's locked in tight.

I'm working to see if I can borrow a PSU off a friend. I guess that would probably be my best troubleshooting step next. Unless anyone else has a suggestion...
m
0
l
a b B Homebuilt system
a b ) Power supply
a b V Motherboard
October 28, 2011 3:50:25 AM

Hmm, I've been thinking about this one. It almost sounds like your CPU is getting too Hot which would cause it to shut down to protect itself. Here's something you can look into to find out. Go into your BIOS and get into the system monitor menu and then just watch your CPU temp for a few minutes. If your CPU is getting hot you will see the temp climb until it shuts down. Normal idle CPU temps are usually about 10-20 Degrees C above room temp when your CPU cooler is working normally. Therefore, if your room is at 25 degrees C you should see your CPU temp get no higher than 40-45 degrees C. Under heavy load it will go higher but in BIOS your basically idling so the CPU temp should be low.

If you find your CPU temps are too high then your Cooler is not working. This is usually due to poor contact with the CPU so remove the cooler, CLEAN the old Thermal paste off thoroughly from the CPU and the Cooler, then Reapply a THIN coating of Thermal paste and reinstall the Cooler being very careful to keep even pressure on all of the screws when you tighten it down.
m
0
l
!